Endovascular thin film devices and methods for treating and preventing stroke

Abstract

Devices for excluding aneurysms and treating atherosclerotic disease, for intra-aneurysmal occlusion, and devices for preventing distal emboli. The devices are generally pliable and collapsible thin film devices which can be delivered via a microcatheter into the desired location where they are deployed and undergo either a shape memory phase transformation or in situ polymerization to assume the stable configuration of a permanent endoluminal prosthesis. Prior to being caused to assume their final shape, the devices remain soft, collapsible and pliable to ensure atraumatic delivery through the vascular system. Upon reaching the endoluminal defect in the vessel, the device is extruded from the microcatheter. Devices are also provided for retrieving clots.

What is claimed is:  
     
       1. A thin-film device consisting of an expanse of sputtered thin film NiTi alloy adapted to be deployed at a selected site, comprising 
       a collapsible member, and  
       attached to said member, an expanse of sputtered thin-film Ni—Ti shapememory alloy having a film thickness between about 0.5 to 150 microns, and characterized by  
       (i) a martensitic state,  
       (ii) an austenitic state in which the expanse assumes a preformed, expanded shape about the member, with such in its deployed condition, and  
       (iii) a thin-film transition temperature at which the expanse undergoes a transition from its martensitic state to its austenitic state,  
       wherein deployment of the device at a site having a temperature above the transition temperature is effective to place the expanse in its preformed shape.  
     
     
       2. The device of  claim 1 , wherein said expanse has a thickness of between 2 to 50 microns. 
     
     
       3. The device of  claim 1 , for use within an endoluminal target site, wherein the device is adapted to be delivered to the target by a catheter or guidewire guide assembly, the thin-film expanse is in a collapsed, martensitic condition when the device is delivered by the assembly, and the transition temperature of the expanse is less than about 350° C. 
     
     
       4. The device of  claim 3 , for use at an endoluminal site that is accessible by means of a catheter having an inner lumen, wherein the device is dimensioned to be advanced through the catheter lumen, with the device in its martensite state. 
     
     
       5. The device of  claim 1 , wherein said expanse is fenestrated. 
     
     
       6. The device of  claim 1 , for use as an endoluminal stents wherein said expanse, in its preformed, austenitic shape, forms an open-sided, closed or overlapping-edge tubular sleeve dimensioned to contact the wall segment of the vessel target site, to hold the device in place when deployed at the site. 
     
     
       7. The device of  claim 6 , wherein said member provides an internal skeleton to which the expanse is attached, and the expanse, in its preformed, austenitic shape, forms a tubular sleeve dimensioned to contact the wall segment of the vessel target site, to hold the device in place when deployed at the site. 
     
     
       8. The device of  claim 7 , wherein said member includes proximal and distal collapsible rings, and the expanse, in its preformed, austenitic shape, forms a tubular sleeve having distal and proximal ends attached to the distal and proximal rings, respectively. 
     
     
       9. The device of  claim 6 , which contains a partial, non-circumferential fenestration. 
     
     
       10. The device of  claim 1 , for use as a bifurcated-vessel stent, wherein said member includes a single proximal ring and first and second distal rings, the expanse, in its preformed, austenitic shape, forms a bifurcated tubular sleeve having a single proximal and first and second distal ends attached to the proximal, and first and second rings, respectively, and the device is dimensioned to contact the wall segments of the bifurcated-vessel target site, to hold the device in place when deployed at the site. 
     
     
       11. The device of  claim 1 , for use in retrieving macroscopic objects, such as blood clots, from a blood vessel, wherein said member includes a proximal collapsible ring, the expanse, in its preformed, austenitic shape, forms a sock having an open proximal end attached to said ring and a closed distal end, and the device further includes a remote-access wire attached to the ring for moving the device in a target vessel. 
     
     
       12. The device of  claim 11 , wherein at least a portion of the expanse is fenestrated to allow blood flow through the expanse. 
     
     
       13. The device of  claim 1 , for use as an intra-aneurysmal occlusion device, wherein said member includes a collapsible ring, the expanse, in its preformed, austenitic shape, forms a conical or hemispherical funnel or a sphere having a distal opening attached to the ring, and the distal opening is larger than the aneurysmal opening through which the device is deployed by such a guide assembly. 
     
     
       14. The device of  claim 13 , which further includes a proximal valved opening through which vaso-occlusive material can be introduced into the aneurysm, when the device is deployed therein.